[Radio frequency catheter ablation of arrhythmias with low dose X-ray guided by three-dimensional mapping system in 14 children]

Objective: To assess the feasibility and efficacy of radiofrequency catheter ablation (RFCA) of arrhythmias with low dose X-ray in children guided by three-dimensional mapping system. Methods: Fourteen children with tachyarrhythmia who were transferred to Tianjin Medical University General Hospital after being hospitalized in Tianjin Children's Hospital and underwent RFCA from April 2017 to May 2018 were included.The results of intraoperative electrophysiological examination, intraoperative X-ray dosage,the immediate success rateand complications of RFCA,and the recurrence during the follow-up for at least 6 months were recorded. Results: Among the 14 children, 11 cases were diagnosed with supraventricular tachycardia.Five cases had atrioventricular reentrant tachycardia (AVRT) which included two cases with left accessory pathway and three cases with right accessory pathway, and four cases had atrioventricular nodular reentrant tachycardia (AVNRT), one case had atrial flutter (AFL), one case had both AFL and AVNRT. One case had focal atrial tachycardia, one case had ventricular tachycardia, and one case had premature ventricular contraction. Eleven cases underwent RFCA with zero radiation, and 3 cases underwent atrial septal puncture with low dose X-ray. The exposure amounts were 3.85, 3.23 and 4.67 mGy, respectively. No complications occurred except for one case with AVRT had atrioventricular block and recovered to normal in 25 days after operation.During the follow-up of 7 to 20 months, no arrhythmias had been found in 13 cases, and one case with AVRT and AFL recurred. Conclusion: Under the guidance of three-dimensional mapping system, RFCA of tachyarrhythmia with low dose X-ray in children is feasible.

Carcass and meat quality traits of four commercial pig crossbreeds in China

We evaluated carcass and meat quality traits of two Chinese native crossbreeds Landrace x Meishan (LM) and Duroc x (Landrace x Meishan) (DLM) and two foreign crossbreeds Duroc x (Landrace x Yorkshire) (DLY) and PIC (an imported five-way crossbreed). One hundred and twenty weaned pigs (half castrated males and half females) were reared and slaughtered at a predestinated slaughter age. The general carcass and meat quality traits were measured and analyzed. The DLY and PIC crosses had significantly heavier live weights (93.39 and 96.33 kg, P < 0.01), significantly higher dressing percentages (80.65 and 79.39%, P < 0.05), significantly bigger loin areas (42.69 and 43.91 cm(2), P < 0.001), and significantly more lean carcasses (65.78 and 66.40%, P < 0.001) than LM and DLM. On the other hand, LM had a significantly lower live weight (70.29 kg, P < 0.01), significantly thicker back fat (3.54 cm, P < 0.001), significantly less lean carcasses (46.82%, P < 0.001), and significantly less ham and breech (26.53%, P < 0.05) than the other crossbreeds. Among meat quality parameters, LM had the highest intramuscular fat content (5.02%, P < 0.001) and the smallest fiber area (3126.45 μm(2), P < 0.01). However, PIC showed the lowest pH(1) (5.82, P < 0.01) and pH(2) (5.63, P < 0.01), the highest drip loss (2.89%, P < 0.01), and the lowest intramuscular fat (1.35%, P < 0.001). We concluded that LM and DLM had good meat quality traits but poorer carcass traits than DLY and PIC; DLY had good carcass and meat quality traits; PIC had good carcass traits, but it had less intramuscular fat, lower pH and higher drip loss.

[Effects of dl-tetrahydropalmatine on blood pressure and norepinephrine and epinephrine contents in peripheral tissues]

Administration of dl-tetrahydropalmatine (THP) i.v., ip, and ig lowered the pressure and concurrently slowed the heart rate in anesthetized rats. The hypotensive and bradycardic effects were not produced by injecting THP into the vertebral artery in anesthetized rabbits. These results suggest that the site of hypotensive action of THP may not be a central one. The HPLC coupled with electrochemical detection showed that the contents of norepinephrine (NE) in the heart, aorta, and femoral artery and epinephrine (E) in the adrenal gland were markedly reduced by THP (P < 0.01). A positive correlation was found between the hypotensive effect and the reduction of NE in the aorta and femoral artery (r = 0.97, P < 0.01).